Splitting of the universality class of anomalous transport in crowded media

TL;DR

This paper explores how molecular crowding causes subdiffusive transport, revealing that while the accessible space transition is universal, the transport dynamics depend on narrow channels and are influenced by microscopic details, contrasting with glassy dynamics.

Contribution

It demonstrates that microscopic dynamics significantly influence long-time transport behavior in crowded media, challenging the universality of percolation-based models.

Findings

Percolation transition remains universal for accessible space.

Transport through narrow channels introduces non-universal behavior.

Microscopic dynamics can dominate long-time relaxation, unlike glassy systems.

Abstract

We investigate the emergence of subdiffusive transport by obstruction in continuum models for molecular crowding. While the underlying percolation transition for the accessible space displays universal behavior, the dynamic properties depend in a subtle non-universal way on the transport through narrow channels. At the same time, the different universality classes are robust with respect to introducing correlations in the obstacle matrix as we demonstrate for quenched hard-sphere liquids as underlying structures. Our results confirm that the microscopic dynamics can dominate the relaxational behavior even at long times, in striking contrast to glassy dynamics.